In recent railroad systems, hybrid vehicles have been introduced for energy saving. A hybrid vehicle includes an electric storage device and can travel by using both the energy from an overhead line and the energy from the electric storage device. The electric storage device of the hybrid vehicle discharges for assisting during power running or absorbs and charges the energy during power regeneration.
The electric storage device of the hybrid vehicle generally discharges to assist the own vehicle or charges the regenerative energy of the own vehicle during traveling. It is also considered that the electric storage device of the hybrid vehicle also discharges to assist another vehicle via an overhead line or recovers the regenerative energy of another vehicle.
However, in the conventional railroad system, it has been difficult to switch charge and discharge of the electric storage device at an appropriate timing corresponding to the state of the own vehicle and another vehicle or the state of the electric storage device.